GMT900 Hydroboost Conversion How-to
 

Hello Friends, First of all, :jest: I'm not used on hard braking, you should have seen me braking all the way to work. Guys with vacuum, trust me trash it you will thank me later. Was running on 9 in/vac @ idle wth ?

(¼) Pedal travel = Nice Bite.
(½) Pedal travel = omg-abs-skid.

You won't need a full pedal anymore. "Broblem" is check brake system on message console, no lights what so ever, any electrician please chime in. :hmmm:

But anyways, I would like to thank Pl4yboy and Robert91RS.

Got my whole unit from a scrap yard from Maine for $290 shipped, 2008 40~k miles wrecked express van.

• Booster# 20940395
• P/S Pump# 20756715 (has an extra return port)
• P/S Hose# 15295853 (pump to booster)
• P/S Hose# 15804952 (booster return to pump)
• P/S Hose# 15295840 (booster to gear)
• Pedal# 15906961 (non adjustable)

http://oi47.tinypic.com/2njgjtx.jpg

1. Disconnect the battery.
2. Locate the bolts on the firewall, knee bolster + bolts are going to be P.I.T.A., stupid loctite.

(1) = Bolts
(2) = Brake lights sensor.

http://oi50.tinypic.com/35i5g9i.jpg

3. Carefully disconnect the brake pedal light sensor, Loosen the bolt and remove it. Then unbolt the whole brake pedal.

http://oi47.tinypic.com/biph6g.jpg

Okay, got a slight problem lol.

http://cdn.memegenerator.net/instanc...x/24624930.jpg

The hydroboost seem to have a different pattern. :sigh:
Didn't want to drill the firewall up, sooo...

http://oi47.tinypic.com/2a4nxch.jpg

I re-welded the bolts up to match the existing one. Thanks GM.

After re-locating the bolts.

http://oi48.tinypic.com/29gczyq.jpg

5. Get a power steering removal kit / installation kit for $30, don't use air tools on this lol. Loosen the drive belt, remove the pulley, remove the 3 bolts (front) 1 bolt (back). straight forward.

6. Connect the high pressure line from pump to booster, low pressure line from booster to PS pump.

7. Remove the clip + bolt attaching 2 lines, one coming from the PS cooler, one from PS pump.

http://oi46.tinypic.com/30blksn.jpg

You could splice this but I preferred to go with a hydraulic hose.

http://sphotos-a.ak.fbcdn.net/hphoto...51999577_n.jpg

^ Ryan @ Nitrous Express could make you one. :usa:

I made a small illustration on how to connect the other high pressure line.

(1) Cut the end of the steel line leaving the Hydro.
(2) Cut the end of the steel line going to the PS gear box.
(3) Hydraulic press the two ends with a 3/8" line IIRC.
(4) Optional, you could add fittings to adjust the hose path and weld them to the lines.

http://oi48.tinypic.com/rll007.jpg

http://oi46.tinypic.com/2rzt40g.jpg

http://oi47.tinypic.com/v4p14z.jpg

:hail: ½ line, 4,000 psi burst point.

8. Broblem? No Broblem! :jest: Found out my master cylinder lines are bigger for some reason. 2x Custom male to female fitting for $20.

http://oi47.tinypic.com/1zc0588.jpg

http://oi47.tinypic.com/2m5j9t4.jpg

9. Bleed PS, Bleed brakes.

http://oi49.tinypic.com/ykpiq.jpg

10. Attach and install everything else including the pedal lol, CHECK FOR LEAKS. Enjoy your beer.

Simple and straight forward, any questions hit me up.

where did you get the adapter fittings??

do you know the size fittings for the hydroboost an rack an pinion? id much rather run SS line vs a chopped up pressure line :)



nice write up :thumb: lets make this a STICKY

I am busy right now and not on my laptop, PM me a reminder and I will sticky it when I get home.

Stuck!!!

Thanks bro, I took the same line that goes in to rack, the hydraulic shop used water to cool it off, checked for burr, nada, perfect cut. Everything was done with big *** machines pushing threw lines, once squeezed it's done.

You could ask your local metal workshop for the adapter, It was done with a lathe I believe. :hmmm:

Can you do me a favor and resize the first and last picture so it doesnt make the post so wide? Thanks a lot for thev ery detailed write-up. I need to do this on my truck ASAP.

id have too much in machine work.

too bad no one works in a part store that can get use 2 new fittings vs hacking up ours :(

You can get new fittings, you just need to know what size they are. In his part of the country it is near impossible to find that type of little stuff.

It's also important to note he used the set up from a Van. There is often small differences between a Van and a Truck platform.

It's also important to note you can sometimes reuse your existing Master Cylinder. The bolt spacing on the end of the hydroboost will determine that.

http://oi48.tinypic.com/2gw9xl2.jpg

Final look.

http://oi50.tinypic.com/o8s2dj.jpg

Lubed up. :jest:

http://oi46.tinypic.com/2dc9ye9.jpg

Centric goodness.

Will this cause issues with my factory trailer brake controller? I've heard that the trucks with factory trailer brake controllers have option-specific master cylinders I believe.